our

opal mine

Australias' Largest manufacturerof opal jewellery

About

An old tradition in a historic location – Shop 5 Rundle Mall, Adelaide – has been famous for supplying some of the world’s best quality opals for over 30 years!

This unique tradition of quality and craftsmanship continues with new owners, both being Master Jewellers and expert opal cutters. We are manufacturing seven days a week and ready to offer our expert advice on all the different types of opals available. Adelaide is known as one of the best places to purchase opals as over 70% of the world’s opal is found in the South Australian fields, thus making the raw material more accessible

Unique Opal and Diamond Manufacturers are the largest opal manufacturing jewellers and opal cutters in Adelaide, so you know we are not just salespeople, we are truly experts in what we do! You will see our handmade quality workmanship and range is second to none. Our jewellers work in store, so you can watch them craft raw materials into works of art.

As well as a large and personally selected range, we can take the raw stone, straight from the opal mine, cut it, polish it and set it into a beautiful piece of truly handcrafted jewellery exactly to your specifications – Unique for you, right before your eyes and within hours. We are 100% South Australian owned and operated.

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Our Opal Mine

Unique Opal and Diamond Manufacturers have a beautifully created underground opal mine for you to explore, bringing to you the 'Coober Pedy Experience’ with the convenience of an Adelaide Rundle Mall location. In our mine you can see the veins of real opal as they would naturally occur in the rock and explore different regions of opal mining throughout the Australian opal fields. Take a few minutes to sit down and watch our short documentary on opals, explaining the different types, the regions where they are found and how they are formed.

If you are lucky, one of our friendly jewellers may be in the process of cutting and polishing the raw stone on the equipment located in the mine area, and you can watch this amazing process of shaping and polishing these beautiful opals first hand!

Photos Inside Our Underground Mine

Our Staff

Steven Miles

Steven has extensive knowledge of opal with a passion that began back in 1995 when he was taught the art of opal cutting and polishing at high school at the age of just 13. He then began a jewellery manufacturing apprenticeship in 1997 and within four years was leading a team of jewellers, where he specialised in delicate opal manufacturing and handsetting. Handsetting is an art which not many people have mastered; it means to set opal without the use of glue, the stone uses the metal to hold it in place, making it extremely safe and lasting a lifetime.

Steven holds a Certificate 111 in Jewellery Manufacturing, a Diploma in Opal Cutting and has been a competitor in the annual Workskills Australia Competition for Jewellery.

Tim Sheridan

Tim began working in the jewellery industry in 1998 for a local watch maker. He then paired up with Steven in 2001 and began a jewellery apprenticeship under Steven’s tuition. Tim completed Certificate 111 in Jewellery Manufacturing in 2005 and also has a Diploma in Opal Cutting. He also has been a competitor in the annual Workskills Australia Competition for Jewellery.

He has a very sharp eye for diamonds and has completed a Diploma in Practical Diamond Grading (Gemmological Association of Australia). Steven and Tim have worked side by side ever since and have now, together, built Adelaide’s largest opal manufacturing workshop.

Opals

South Australia produces 80% of the world's supply of opal.

Opals are formed by water seeping through sandstone and picking up tiny pieces of silica. The water and silica combination filled cavities within sedimentary rocks. When climate changed over a period of one to two million years, the water dissolved. Gradually seepage and evaporation caused layering of microscopic silica spheres.

Opal naturally diffracts white light into all the colours of the spectrum. The spherical shape of the silica particles means that there are spaces remaining which contain a water and silica mixture. White light enters the top of the opal and refracts from the silica spheres and the spaces containing a mixture of water and silica. This causes diffraction.

The diameter of the spheres and the spaces containing water and silica causes the colour variation in the stones as it determines the size and angle of the division of white light. Large spheres produce red, small spheres blue and the variance between.

From common through to rare, the spectrum is blue, green, yellow, orange and red. The combinations of colours seen are blue only, blue-green, blue-green-yellow, blue-green-yellow-orange and blue-green- yellow-orange and red. Sometimes the colours can combine resulting in non-primary colours.

How to Care for Your Opal

Opals are a very resilient stone, contrary to many beliefs. Solid opals are fine if immersed, but doublets or triplets are recommended to keep out of water as much as possible as the water may cause a discolouration of the glue holding the surfaces together.

Solid opals are non-porous so are not affected by perfumes or hairsprays.

Cleaning at home can be done by soft cloth or a toothbrush with warm water, but we offer cleaning services in store, and use specialised equipment to bring the opal and it’s setting back to new. Care should be taken not to drop your opal on a hard surface as they can chip or crack (as with most other gemstones).

Choosing Your Opal

When choosing an opal, whether a doublet, triplet or solid opal should be purchased, depends upon the piece of jewellery and how it will be worn i.e. a ring is more susceptible to getting wet, therefore a doublet or triplet might be more appropriate as a pendant.

A solid opal is easier to take care of as it is not susceptible to liquids, and can be worn carefree.

The choice between crystal, boulder, black etc is a personal preference for most customers. There are charms to each variety of stone, so it depends on which one speaks most to you. Shades of red are the rarest find within opals, and therefore stones featuring red tend to be considered more valuable, especially in a black opal where the colour can be extremely rare, however the preference of colours within the stones are again personal.

Types of Opals

Precious and Common (also known as potch) are the two main types of opal. Precious opals display intense colour. Common opal is milky with no colour displayed. It is often used as backing for doublets or triplets. More specifically, opals can be categorised into the following types:

Black Opal

Black opal is found at Lightning Ridge, north west of Sydney in New South Wales. It is so named from the black rock base which causes the refraction of colours to be brighter, although this may be just a thin colour strip on black potch. Black opal is the rarest and most valuable of all the opals due to the intense colours, clearness and patterns, ranging from blues and greens to red, although red on black opal is extremely rare and therefore the most expensive.

White Opal

White opal is mainly mined at Coober Pedy, Andamooka and Mintabie in South Australia. The very light or milky coloured base of the opal allows a wonderful spectrum of subtle colours from blues, greens to reds to shine through. 80% of all opal is mined is these harsh South Australian Outback towns.

Boulder Opal

Boulder opal is mined in Queensland’s vast areas of the Australian Outback. It is naturally formed by bonding to sedimentary ironstone rocks, resulting in beautiful darker stones. Sometimes the brown ironstone is visible on the surface of the stone, giving attractive contrasts to the sparkling rainbow colours of the opal. This opal forms in very thin vertical and horizontal strips in the cracks of the rock. Depending on the quality of the boulder, these opals are extremely valuable, second only to the very rare black opal.

Crystal Opal

Crystal opal is also mined in South Australia. Crystal opals are transparent, or semi-transparent gems, thus allowing the beautiful array of colours to shine through the translucency. They are usually of a higher quality than white opal, and therefore more expensive.

Doublet Opal

Doublet opals are a thin layer of crystal opal glued to a black backing, either a layer of potch or ironstone, using epoxy resin. This gives the resemblance of a black or boulder opal but at a fraction of the cost; however they can be easily identified by examining the opal from a side view, when the black backing will be clearly visible as a straight line meeting the thin layer of opal.

It is advisable not to immerse these opals in any water or liquid as this may infiltrate between the backing and the opal causing a discolouration of the resin, and eventually separation of the layers. Doublets are more expensive than Triplets as a thicker layer of opal is used.

Triplet Opals

Triplet opals are produced in similar way to Doublets, but using a thinner layer of opal, and a clear layer of quartz is glued over the top forming a dome called a cabochon. This gives the stone a smooth, glass like appearance which reflects light differently. This can magnify the opal colour, but is mainly for protection. Triplets like doublet opal should not be immersed in liquid. Triplets are less expensive than doublets as less opal is used.

Diamonds

At Unique Opal and Diamond Manufacturers we also specialise in custom handmade diamond jewellery. We have an extensive knowledge on all types of diamonds and can help you pick that special stone for that special someone!

India is reputed to have been first to recognise and mine diamonds – between 3,000 and 6,000 years ago! The name 'diamond’ originated from the ancient Greek word adamas, meaning 'unbreakable', 'proper’, 'unalterable’.

In the 20th century, NW Ayer & Son for De Beers ran a very successful marketing campaign coining the slogan “a diamond is forever”. This campaign is thought to be responsible for the modern popularity of the stone in jewellery.

Pearls

At Unique Opal and Diamond Manufacturers we have a large range of pearl jewellery and loose pearls ready to be created into your personal designs, so you can be sure of selecting some beautiful pearl pieces to match your style and price range!

NATURAL PEARLS form when sand or grit enters the soft shell of a living mollusc or oyster. The mollusc perceives this as a foreign body and so produces layers of nacre to surround the invader and protect itself, which over time forms into the pearl.

FRESHWATER PEARLS, as the name denotes, are similarly formed, found in freshwater mussels in lakes, ponds and rivers. Freshwater pearls are less expensive than natural pearls, making them more affordable, however they do not have the same degree of lustre, but do come in a variety of shapes and colours making them very attractive.

TAHITIAN PEARLS, come from the South Sea and French Polynesian islands. These pearls are formed in the much larger black-lipped oyster, pinctada margaritifera, thereby obviously producing much larger pearls. These pearls cover a broad range of colours including much darker varieties.

SOUTH SEA PEARLS, which are formed in the pinctada maxima oyster, are of the highest grade and come in lighter, rich lustrous shades of silver and golden hues. Due to the huge colour range and varying pearl sizes, matching the pearls to create one single strand makes them much more expensive. These pearls are sourced from the northwest coast of Australia.

How are Pearls formed?

When a microscopic parasite enters a bivalve mollusk inside the sheel, it causes the mollusk to secrete calcium carbonate and conchiolin and form a pearl sac of external mantle tissue cells, forming a natural pearl.

Natural pearls can come in many attractive shapes, and perfectly round is very rare.

The trade name of cultured pearls are Akoya, white or golden South Sea, and black Tahitian pearls and they are formed by implanting an irritant into a shell, such as a sperical bead.

Imitation pearls are made of mother-of-earl, coral or conch shell, glass, or are coated with a solution containing fish scales (known as essence d’Orient). They do not have the same weight or smoothness of real pearls, and their lusture will dim.

Types of Pearls

Pearl necklaces are named according to how low they hang when worn around the neck.

A choker is 35 to 41 cms
A collar is 25 to 33 cms
A Princess length is 43 to 48 cms
A matinee length is 50 to 60 cms
An opera length is 70 to 90 cms
A pearl rope is more than 115cms in length, or any length longer than an opera

Grading of Pearls

Pearls are identified using advanced gemmological testing equipment, including x-rays, UV reflection etc. This determines colour,grade and the diameter size.

The value of the pearls in jewelry is determined by a combination of the luster, color, size, lack of surface flaw and symmetry that are appropriate for the type of pearl under consideration. Among those attributes, luster is the most important differentiator of pearl quality according to jewelers.

All factors being equal, however, the larger the pearl the more valuable it is. Large, perfectly round pearls are rare and highly valued. Teardrop-shaped pearls are often used in pendants.

In general, cultured pearls are less valuable than natural pearls, whereas imitation pearls have almost no value. One way that jewelers can determine whether a pearl is cultured or natural is to have a gemlab perform an X-ray examination of the pearl. If X-rays reveals a nucleus, the pearl is likely a bead-nucleated saltwater pearl. If no nucleus is present, but irregular and small dark inner spots indicating a cavity are visible, combined with concentric rings of organic substance, the pearl is likely a cultured freshwater.

Custom Opal Pieces

Our expert jewellers specialise in taking the straight-from-the-mine raw opal and polishing it, so they have a large range of unset stones available. So if you do not see what your heart desires amongst our existing created stock, talk to Steven or Tim about your ideal design and they can craft by hand exactly what you want.

We can custom make jewellery in any gemstone and metal. If you are searching for something Unique for your special occasion, come and see us. We can work with you on the design and offer a wide selection of stones from which to choose.

If you would like to see some of the gorgeous pieces we create on a daily basis, like our Facebook page and view our posted photos.

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